Paul Rotha recalled in his autobiography: "one afternoon in March 1936, two or three of us at Strand Films were looking down from the third-floor windows at the newspaper placards outside Frascati's Restaurant in Oxford Street. They shouted BRITAIN TO RE-ARM. One of us said, 'Why the hell are we making films if we don't do something about urging people to demand peace by collective security?'"

The result was this punchy three-minute cine-poster, often known simply as 'the peace film', partially funded by the ascetic left MP, Stafford Cripps. It combines music by Benjamin Britten in interplay with bold captions, a variety of voices, four 'vox-pops' and (mainly library) footage to put across its message, to "demand peace by reason", by writing to your MP.

Rotha was no exception to the political rule in documentary: most documentarists were proud of being leftists, but few were communists. The mildness of the political prescription here is typical of the documentary 'movement'. But it still caused a minor political storm; one of the lengths of library film, showing an American tank, was the ostensible cause of a hold-up at the British Board of Film Censors, who asserted that the footage might be Crown copyright.

The delay at the censors did the film much good. Rotha orchestrated a publicity campaign; the film was granted a certificate, and it ended up being shown in 570 British cinemas and seen by an estimated 2.3 million people.